Polygonal section spar platform for drilling and production

ABSTRACT

The present invention relates to a polygonal section spar platform for drilling and production, which can raise efficiency in process and production and reduce manufacturing costs by making a section of a drilling and production spar platform in a polygonal shape. The drilling and production spar platform comprises a ballast tank, a spar hull, a mooring fairleader, a trim tank and a fixed ballast, wherein the spar hull, which is an underwater portion of the drilling and production spar platform, has a section being in the form of a polygon. By such spar platform, the present invention can largely increase the manufacturing performance and production and promote a general operational efficiency.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a polygonal section sparplatform for drilling and production, and more particularly, to apolygonal section spar platform for drilling and production, which canlargely promote a general operational efficiency and reducemanufacturing costs by sharply increasing the manufacturing performanceand production of the spar platform, which operates in the deep sea.

[0003] 2. Description of the Related Art

[0004] In general, there are fixed type or floating type drilling shipsor rigs to search oil and to drill for oil: the fixed type being ajack-up drilling rig, a jacket and the likes, which are fixed on theseabed, and the floating type being a semi-submersible drilling rig, atension-leg platform, a spar and the likes.

[0005] Recently, according to the exhaustion of oil resources, there isa difficulty in use of the fixed type drilling ships or rigs because thesearch and the drilling for oil are performed in deeper water, andtherefore, the use of the floating type drilling ships or rigs is on anincreasing trend all over the world. In particular, a drilling andproduction spar platform of the floating type drilling ships or rigs haslately attracted considerable attention.

[0006] As shown in FIG. 3, a typical drilling and production sparplatform 20 has a section being in the form of a round. However, suchspar has a difficulty that a steel sheet must be bent into a round of 30m to 50 m in diameter in the manufacturing process. Furthermore, thereare several problems that the manufacturing process is very difficultand complex and many man-hours and efforts are required since a frame 21of a transverse strength element or a strength web frame 22 and alongitudinal strength element 23 are made in the form of a circle, andmust be exactly bonded and welded to an external sheet of a circle form.

SUMMARY OF THE INVENTION

[0007] It is, therefore, an object of the present invention to provide apolygonal section spar platform for drilling and production, which canraise efficiency in process and production and reduce manufacturingcosts by making a section of a drilling and production spar platform ina polygonal shape.

[0008] To achieve the above object, the present invention provides adrilling and production spar platform comprising a ballast tank, a sparhull, a mooring fairleader, a trim tank and a fixed ballast, wherein thespar hull, which is an underwater portion of the drilling and productionspar platform, has a section being in the form of a polygon. By suchspar platform, the present invention can largely increase themanufacturing performance and production and promote a generaloperational efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Further objects and advantages of the invention can be more fullyunderstood from the following detailed description taken in conjunctionwith the accompanying drawings in which:

[0010]FIG. 1 is an exemplary view of a section of a drilling andproduction spar platform according to the present invention;

[0011]FIG. 2 is an exemplary view of the drilling and production sparplatform; and

[0012]FIG. 3 is an exemplary view of a typical drilling and productionspar platform.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0013] The present invention will now be described in detail inconnection with preferred embodiments with reference to the accompanyingdrawings. For reference, like reference characters designatecorresponding parts throughout several views.

[0014]FIG. 1 is an exemplary view of a section of a drilling andproduction spar platform according to the present invention, and FIG. 2is an exemplary view of the drilling and production spar platform. Asshown in FIG. 2, a drilling and production spar platform 10, which is acylindrical floating structure having a diameter of about 30 m to 50 mand a length of about 200 m, includes a ballast tank 11, a spar hull 12,a mooring fairleader 13, a trim tank 14 and a fixed ballast 15. As beingsmall in vibration caused by wave, the drilling and production sparplatform 10 has little vibration even in poor surroundings of deep waterand high wave, thereby performing a production work throughout the year,using only a common riser without using a high-priced flexible riser,and easily securing a space for storing produced crude oil.

[0015] In the present invention, the spar hull 12 of the drilling andproduction spar platform 10 having a round shape has a section of apolygonal shape having a specific angle depending on preference of adesigner or a user and on the surroundings of a navigation area, and aframe of a transverse strength element and a longitudinal strengthelement are bonded and welded to the polygonal spar hull.

[0016] That is, as shown in FIG. 1, the spar hull 12, which is anunderwater portion of the drilling and production spar platform, is madein the form of a triangle 121, a quadrangle 122, a pentagon 123, ahexagon 124, an octagon 125, a nonagon 126, . . . , and all possiblepolygons to be suitable for the surroundings of the navigation area, andthe frame of the transverse strength element or a wed frame and thelongitudinal strength element are bonded and welded to the spar hullhaving the polygonal section.

[0017] Furthermore, because the section of the spar hull 12 of thedrilling and production spar platform 10 is formed in a polygonal shape,it is possible to reinforce and use a corner part of the polygonal sparhull or the spar hull part having the polygonal section, to which theframe of the transverse strength element or the wed frame and thelongitudinal strength element are boned and welded.

[0018] As previously described, the section of the drilling andproduction spar platform is formed not in the round shape but in thepolygonal shape, thereby reducing the manufacturing costs, largelyincreasing the manufacturing performance and production of the sparplatform, and promoting an operational efficiency.

[0019] While the present invention has been described with reference tothe particular illustrative embodiments, it is not to be restricted bythe embodiments but only by the appended claims. It is to be appreciatedthat those skilled in the art can change or modify the embodimentswithout departing from the scope and spirit of the present invention.

What is claimed is:
 1. A drilling and production spar platformcomprising a ballast tank, a spar hull, a mooring fairleader, a trimtank and a fixed ballast, wherein the spar hull which is an underwaterportion of the drilling and production spar platform, has a sectionbeing in the form of a polygon.